1. Field of Invention
This invention relates to systems for processing receiver data. Specifically, the present invention relates to radar data processing systems adapted for use with pulsed radar systems.
2. Description of the Related Art
Radar systems are used in a variety of demanding applications including air traffic control and missile guidance. Such applications often require radar systems to effectively track a target in electrically noisy environments and receive messages from an external transmitter.
Tracking ability and message reception are particularly important in missile guidance applications where pulsed radar systems are employed. A pulsed radar system typically includes a receiver, a transmitter, and a digital signal processor such as a missile mission computer. The transmitter transmits radar signals in the direction of a target. The radar signals reflect off the target and are received by the receiver. The receiver may also receive data link messages such as steering commands from an aircraft-based missile guidance system. The digital signal processor facilitates processing of the received signals and may also provide commands to facilitate missile target tracking.
Typically, received commands or radar signals are collected and processed during predetermined time intervals called dwells. The processing of signals received during a previous dwell occurs during a subsequent dwell. An inter-dwell period exists between dwells to allow for the reconfiguration of data processing circuits and other hardware in response to the processed data of the most recent dwell. Any processing of received signals or collecting of received signals is typically halted during this inter-dwell period.
The radar system transmits or receives signals within a predetermined frequency band, i.e., channel. Radio frequency interference may corrupt the channel making it unusable. The radar system determines if the channel is corrupted with radio frequency interference (RFI) after processing received signals. If the channel is corrupted with RFI, commands are often generated to assign the radar system to the next channel upon completion of the current dwell. However, if the next channel is also corrupted with RFI, the radar system cannot make the determination until the completion of the next dwell. If several corrupted channels are assigned to the radar system in sequence, valuable time is lost. During this time, the missile cannot detect targets or update track files.
External missile guidance systems often employ data link messages to transmit data such as steering commands to an airborne missile. To receive a data link message, the missile radar system employs either a dedicated receiver or must time-share the radar receiver for synchronous data link messages. Such time-sharing detracts from radar receiver resources. Dedicated receivers increase system cost and complexity and are usually avoided if the application can tolerate the associated performance penalty.
Hence, a need exits in the art for a radar system that can efficiently handle data link messages and account for RFI without requiring the use of additional dwells. There is a further need for a system that can support asynchronous messaging to improve system flexibility and performance.